The present invention relates to devices for killing insects by electrocution and, more particularly, to a device of electronic character for killing insects by electrocution.
It has heretofore been known to utilize AC voltage for killing insects by applying the voltage across spaced electrodes and with the insects being attracted toward the electrodes by fluorescent lighting.
For this purpose, devices have been sold commercially which employ simple step-up transformers for stepping up conventional 60 Hertz AC line voltage to a level suitable for electrocuting insects which come into contact or close proximity to electrodes across which the 60 Hertz higher voltage is present. To provide sufficient current for this, the transformer is required to be large, bulky, clumsy and expensive.
Moreover, in practice a very high failure rate has occurred with such transformers. The failure mode resulting in a failure rate is not well understood but is believed to result in part from high temperature causing dielectric breakdown and in part because of the transmigration of the winding elements (e.g., copper) to the opposite ends of the transformer core, possibly the result of corona which is characteristic of such transformers. The transmigration of elemental constituents eventually causes shorting of the turns. But regardless of the reasons for such frequent failure, it is undesirable and has caused conventional insect electrocuters to be less commercially successful than would otherwise be the case.
A further disadvantage of the use of such simple transformers for stepping up the 60 Hertz AC line voltage is that voltage regulating devices must be connected across the secondary winding to prevent extensive voltage variations which could cause arcing between electrodes and which can result from poor transformer voltage tolerances. Also, high voltage variations could preclude obtaining safety certification of such devices by testing and certification agencies such as Underwriters' Laboratories, Inc.
A related shortcoming of these prior art electrocuters is that, due to size limitations and current output restrictions at 60 Hertz which are necessitated by such certification, the electrocuter may be electrically overloaded or shorted by insect carcasses clinging to the electrodes since typically electrocuters have lacked sufficient power to carbonize the carcasses. Hence, these prior art devices sometimes clog with dead insects. Short circuit protection is required in prior art devices to protect against damage to the transformer from such shorting of the electrodes.
As noted, fluorescent lighting has been used in prior art electrocuters to attract insects. The fluorescent lamps have required the use of lamp ballasts which are known to be space-consuming, heavy, and expensive. The ballasts also generate heat which may contribute to the failure of other components in the electrocuters, such as the above-mentioned step-up transformers.
Such problems of the prior art have been long outstanding and have remained unsolved.
An object of the invention is the provision of a device for killing of insects by electrocution, which device is electronic.
A further object of the invention is the provision of such an electronic insect killer which utilizes a high efficiency, compact, low cost, high power, reliable, and lightweight solid state ciccuit.
Another object of the invention is the provision of such an electronic insect killer which is not prone to electrical failure, clogging by insects or self-destruction by short circuiting.
Yet another object of the invention is the provision of such an electronic insect killer including such a solid state circuit which not only develops high voltage for insect electrocution but also produces lower voltage for energizing fluorescent lamp means to attract insects toward the electrodes.
Yet another object of the invention is the provision of such an electronic insect killer including solid state circuitry for energizing such fluorescent lamp means without ballasting.
A still further object of the invention is the provision of such an electronic insect killer which develops sufficient electrical energy for carbonizing insects to avoid clogging, overloading, short circuiting of electrodes, etc. by insect carcasses.
A further object of the invention is the provision of such an electronic insect killer which develops such high electrical energy without compromising safety.
Yet another object of the inventon is the provision of such an electronic insect killer which is self-regulating and is by design self-protected against short circuiting.
Still another object of the invention is the provision of such an electronic insect killer which utilizes electrically efficient components which develop relatively little heat.
Among still other objects of the invention may be noted the provision of such an electronic insect killer which conduces to economical mass production, simple assembly, facile repair, which is simple and effective in design, and which kills flies, mosquitoes and myriad other species of various flying insects.